1. Field of the Invention
The present invention relates generally to direct broadcast satellite systems, and in particular, to a tri-head KaKuKa feed for a single-offset dish antenna.
2. Description of the Related Art
Satellite broadcasting of communications signals has become commonplace. Satellite distribution of commercial signals for use in television programming currently utilizes multiple feedhorns on a single Outdoor Unit (ODU) which supply signals to up to four Integrated Receiver-Decoders (IRDs) on separate cables from an integrated multiswitch. Additional IRDs can be serviced with external cascaded multiswitches.
DIRECTV® currently broadcasts video programming signals from transponders on three satellites in three different orbital slots located at 101 West Longitude (WL), 119 WL, and 110 WL, also known as Sat A, Sat B, and Sat C, respectively. The FCC (Federal Communications Commission) has allocated to DIRECTV® transponders 1–32 on 101 WL, transponders 22–32 on 119 WL, and transponders 28, 30, 32 on 110 WL.
These satellites broadcast in the Ku-band of frequencies, typically between 12.2 GHz and 12.7 GHz. Additional satellites are currently being contemplated for use with the DIRECTV® system, which will broadcast in the Ka-band of frequencies, typically between 18 and 20 GHz. The additional satellites can be placed on-orbit at any location, but currently, the locations are expected to be at 99 WL and 103 WL. Additional satellites may be placed at other locations, such as 101 WL.
Although additional ODUs can be installed to receive the Ka-band frequencies, installation of an additional ODU at a given location may be difficult, as well as costly. Further, multiple ODU installations will be difficult to connect to existing systems, because of potential additional cable runs as well as possible interference with existing equipment.
It can be seen that there is a need in the art for an ODU that can receive both Ka-band and Ku-band signals. There is also a need for a method that takes into account the position of the satellites that are transmitting these frequencies, as well as designing the ODU to maximize the signal strength from the Ka-band.